1. Field of the Invention
The present invention relates generally to a safety device and particularly to a safety device for use in situations where it is necessary to maintain consciousness or at least awareness. Such situations include, without limitation, those where an individual at risk may be otherwise unsupervised.
2. Description of the Related Art
In a hospital or like environment it is important that the consciousness or awareness status of an individual is known to the staff. This is of the utmost importance in connection with patients whose state of health is uncertain, such as patients undergoing tests, those in hospital for observation or those convalescing or recovering from an operation. However, there are situations where a patient is not usually supervised, for example, toilet cubicles or washing facilities. If a patient falls ill and becomes unconscious or partly conscious whilst unsupervised in these situations it may be some time before they are found and located so that their condition can be attended to.
Toilet cubicles are particularly relevant in the case of people at risk of cardiac arrest, major pulmonary embolus or hypoglycaemia. It is known that many people have a circulatory arrest whilst in a toilet. This is not coincidental but rather, at least in part, because the vagal reaction makes them think that they need the toilet when it may in fact be an early response to the events leading to the collapse.
There are, of course, other circumstances where consciousness or awareness indications are required. For example it has long been the practice to provide the driver's cab of a railway locomotive with a device known as a “dead man's handle” which is to be maintained in an operative state by the train driver in order to ensure that he has not fallen asleep as a result of the essentially tedious nature of this task.
Some toilets and bathrooms are provided with emergency cords which must be pulled to trigger a signal to attract attention. However, it may not always be possible for the patient to pull such a cord, for example because they have fallen on the floor and/or are unconscious, or because they have become disorientated or confused as a result of a medical condition.
There exists the need for a device which requires a patient to do something positive to demonstrate that they do not need assistance.
Accordingly, the present invention provides sensor means for monitoring the awareness status of an individual within a monitored environment, comprising means for determining the attainment of at least one predetermined condition identifying the requirement for the awareness of an individual to be monitored, and operative to trigger an alarm, means operable by the monitored individual for inhibiting the operation of the alarm, and delay means for delaying the triggering of the alarm for a predetermined period after the attainment of the said predetermined condition.
The monitored environment may comprise an enclosed space. In a preferred embodiment the safety device is designed for use in a lavatory cubicle; however, other situations where individuals are not normally supervised, such as bathrooms or shower cubicles, are not beyond the scope of the invention.
The condition identifying the requirement for the awareness of an individual to be monitored may be no more than the presence of the individual in the monitored environment.
The means for detecting the presence of an individual may act either indirectly, for example by sensing operation of a door lock, or by remote sensing means sensitive to the presence of an individual within a range thereof, such as an infra red or other light beam or an ultrasonic detection means. In any case it is preferable that the individual cannot be present in the monitored environment without being detected. In the case of a door lock for a toilet it is therefore preferable that the associated door is biased to be open, by any suitable means, such as a spring. The lock is then required to hold the door closed so that an individual will be encouraged by this so not use the toilet without locking the door, and in doing so identify the requirement for him or her to be monitored.
In an alternative embodiment the device itself may be attached to or worn by a monitored individual and set to detect when the individual enters an otherwise unsupervised environment, for example a stairwell where visual monitoring by staff is not available. When in this environment, the user must maintain a button pressed or provide other awareness indication to prevent triggering of an alarm.
The positioning of the means for inhibiting the alarm within the monitored environment and its operation is preferably dictated at least in part by ergonomic considerations, so as to be accessible, comfortable and not inconvenient for the monitored individual to use. The means for inhibiting the alarm may be fixed in its position or movable to a limited extent to allow positioning for convenient use by a user regardless of his or her position in the monitored environment. Likewise all, or part of the means for inhibiting the alarm may be adjustable for the comfort and convenience of the monitored individual.
The means for inhibiting the alarm may be formed so as to be operable whilst a monitored individual is seated or standing and may be operable for example by a limb, hand, foot or digit, the general principle being that the action must be one requiring sentient control.
In a preferred embodiment the means for inhibiting the alarm is a push button pressed by a foot. However other suitable arrangements such as a pedal or hand-operated lever or one positioned to be operated by a knee, or a switch to be operated by a digit are not beyond the scope of the invention.
In a preferred embodiment the means for inhibiting the alarm is a push button which is located on the floor and is upstanding therefrom. It may be preferable, however, for the means for determining the attainment of a predetermined condition and/or the means for inhibiting the alarm to comprise a member which does not protrude substantially above the level of an associated surface so as not to present a risk of tripping. For example the member may comprise a laminar element such as a pressure pad to be placed on the floor whereby to be substantially level therewith, a membrane switch or a sunken button. A laminar element may be sensitive to pressure over part of its surface; markings or other visible indicia such as coloured areas may be provided to identify the required position of the user's feet or other actuating member.
For the visually impaired tactile indicators may be provided, such as surface roughening or small projections.
This principle could also be applied to the means for determining the requirement for monitoring the individual. For example a pressure pad or membrane switch could be positioned at the entrance of the monitored environment so as to be triggered as the individual enters.
The means for inhibiting the alarm may be resiliently biased to the alarm-activating position so that the bias has to be overcome by muscular effort to prevent the alarm from sounding.
In order to avoid the possibility that the operating limb, hand or foot may remain on the means for inhibiting the alarm following unconsciousness or illness, it is desirable for the alarm-inhibiting means to require deliberate muscular effort to maintain it in its operating position so that muscular relaxation upon loss of consciousness will result in the alarm being raised. The effort required to operate the means for inhibiting the alarm is therefore preferably more than that which could be satisfied merely by placing the weight of the limb, hand or foot on it.
It is preferable that the bias acts in such a way that it is unlikely that an individual could or would wish to act against it, either deliberately or inadvertently whilst in need of assistance. The required effort may be variable.
Although operation of the means for inhibiting operation of the alarm must be deliberate, the operation does not have to be continuous. For example, in the case of a lever which is pushed down, the lever may gradually return to its starting position, whereby the individual must periodically depress the lever to prevent activation of the alarm.
The means for inhibiting the alarm may further include a guard member or element which may be positioned to inhibit accidental operation.
In a preferred embodiment the guard comprises a U-shape raised collar and a push button is located in the recess defined therein. However, other means such as a flap or cover which must first be removed could also be envisaged.
The alarm may consist of audible, visual or other appropriate signals to alert the attention of supervising staff. The alarm may be localised to the area of the means for inhibiting the alarm and/or may be connected to a central monitoring system. Connection of the sensor means to the alarm and/or a central monitoring system may be direct or by telemetry.
The system preferably has means to avoid inappropriate activation of the alarm. For example, in the case of a toilet cubicle, in the normal course of events when an individual has finished using the toilet and wishes to leave the cubicle or wants to adjust the position of his or her foot he or she may have to release the means for inhibiting the alarm; it is undesirable for the alarm to sound immediately. This may be overcome by having a predetermined delay between such release and sounding of the alarm; any such time delay should not, however, be so long as to endanger a user with a genuine emergency.
Once the requirement for monitoring the individual is satisfied there may also be provided warning means which operate during the predetermined period after the attainment of this predetermined condition. The warning means will therefore be effective to serve as a reminder to operate the means for inhibiting the alarm, both initially as the individual enters the monitored environment and at any time during their occupation for example if they remove their foot to adjust its position, until the means for inhibiting the alarm are activated or the individual leaves the enclosed space. The warning means may comprise means for generating an audible; the signal may increase in frequency with time.
The system is preferably co-ordinated with the presence detector so that the alarm function is inactivated once the individual has left the cubicle. There may also be provided further means for deliberately inactivating the alarm function, for example a key held by a responsible person which may be used if the alarm has activated and staff are in attendance, the alarm no longer being required.
In the case of patients whose mental or physical state makes it unlikely or impossible for them to operate an alarm-inhibiting device requiring sentient muscular control it may be necessary or desirable to have an individual such as a healthcare auxiliary in close proximity to the monitored environment. In such cases there may be provided second means for inhibiting the operation of the alarm located externally of the monitored environment and operable by a supervisor able to maintain supervision of the monitored environment. In this case the second alarm-inhibiting means effectively ensures that the monitoring takes place.
To prevent the triggering of the alarm, operation of the second means for inhibiting the alarm may be required in addition to or instead of the means operable by the monitored individual. In the first case, operation of the second means could be used to ensure that the healthcare auxiliary remains in place in close proximity to the monitored environment. In the second case, operation of the second means could be used where the monitored individual, because of disability or mental state, is unable to operate the means for inhibiting the alarm, the healthcare auxiliary inhibits the alarm but is in close proximity to the monitored environment and may periodically assess their awareness, for example by speaking to the monitored individual to get a verbal response.
The second means for inhibiting the alarm may function in the same way as the means for inhibiting the alarm operated by the monitored individual, in that the means are resiliently biased to an alarm-activating position (such as a normally-closed switch) and require a continuous conscious action, such as pressing a button, to avoid triggering the alarm.
If the alarm sounds for any reason the lock of the cubicle door may automatically be opened to allow access to the individual. In hospitals this would not usually be needed because cubicles are normally equipped with means by which they can be opened from outside in an emergency.
The system may be retrofitted to existing enclosed spaces or installed upon initial construction.